12 14 600 Removing/replacing knock sensors (N52, N52K, N51): Notes

No steel screws/bolts may be used due to the threat of electrochemical corrosion.

A magnesium crankcase requires aluminium screws/bolts exclusively.

Aluminium screws/bolts must be replaced each time they are released. 

Aluminium screws/bolts are permitted with and without color coding (blue).

For reliable identification:

Aluminium screws/bolts are not magnetic. 

Jointing torque and angle of rotation must be observed without fail (risk of damage).